2 files changed, 14 insertions, 0 deletions

diff --git a/include/uapi/linux/if_tunnel.h b/include/uapi/linux/if_tunnel.h
index 7c832afdfa94..280d9e092283 100644
--- a/include/uapi/linux/if_tunnel.h
+++ b/include/uapi/linux/if_tunnel.h
@@ -64,6 +64,7 @@ enum {
 enum tunnel_encap_types {
         TUNNEL_ENCAP_NONE,
         TUNNEL_ENCAP_FOU,
+        TUNNEL_ENCAP_GUE,
 };
 
 #define TUNNEL_ENCAP_FLAG_CSUM          (1<<0)
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index d9c9dc4ffeaf..0bb8e141eacc 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -56,6 +56,7 @@
 #include <net/netns/generic.h>
 #include <net/rtnetlink.h>
 #include <net/udp.h>
+#include <net/gue.h>
 
 #if IS_ENABLED(CONFIG_IPV6)
 #include <net/ipv6.h>
@@ -495,6 +496,8 @@ static int ip_encap_hlen(struct ip_tunnel_encap *e)
                 return 0;
         case TUNNEL_ENCAP_FOU:
                 return sizeof(struct udphdr);
+        case TUNNEL_ENCAP_GUE:
+                return sizeof(struct udphdr) + sizeof(struct guehdr);
         default:
                 return -EINVAL;
         }
@@ -546,6 +549,15 @@ static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
         skb_reset_transport_header(skb);
         uh = udp_hdr(skb);
 
+        if (e->type == TUNNEL_ENCAP_GUE) {
+                struct guehdr *guehdr = (struct guehdr *)&uh[1];
+
+                guehdr->version = 0;
+                guehdr->hlen = 0;
+                guehdr->flags = 0;
+                guehdr->next_hdr = *protocol;
+        }
+
         uh->dest = e->dport;
         uh->source = sport;
         uh->len = htons(skb->len);
@@ -565,6 +577,7 @@ int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
         case TUNNEL_ENCAP_NONE:
                 return 0;
         case TUNNEL_ENCAP_FOU:
+        case TUNNEL_ENCAP_GUE:
                 return fou_build_header(skb, &t->encap, t->encap_hlen,
                                         protocol, fl4);
         default: